Antenna base



FIG. 1 is a front plan view of an antenna base showing my new design;

FIG. 2 is a rear plan view thereof;

FIG. 3 is a left side plan view thereof;

FIG. 4 is a right side plan view thereof;

FIG. 5 is a top plan view thereof;

FIG. 6 is a bottom plan view thereof;

FIG. 7 is a front perspective view thereof; and,

FIG. 8 is a rear perspective view thereof.

The broken lines illustrate portions of the antenna base that form no part of the claimed design. 

CLAIM The ornamental design for an antenna base, as shown and described. 